In general, a stereoscopic image, which is expressed in three dimensions, is formed according to a stereoscopic principle based on two eyes. A depth effect is obtained through binocular parallax caused by a distance of about 65 mm between the two eyes.
Consequently, the left and right eyes view different two-dimensional images, which are transmitted to the brain via the retina. The brain combines the two images to reproduce the depth and realism of the original three-dimensional image. This is generally called stereography.
Based on whether glasses are worn, a stereoscopic image display apparatus is generally classified as a stereoscopic type stereoscopic image display apparatus or an autostereoscopic type stereoscopic image display apparatus. The autostereoscopic type stereoscopic image display apparatus is generally classified as a lenticular type stereoscopic image display apparatus or a parallax-barrier type stereoscopic image display apparatus.
A conventional parallax-barrier type stereoscopic image display apparatus will be described with reference to FIGS. 1 and 2.
The conventional parallax-barrier type stereoscopic image display apparatus includes a display module 10, on which left images L and right images R corresponding to a left eye and a right eye, respectively, are alternately arranged in a horizontal direction (an X-X′ direction in FIG. 2), the left images L and the right images R extending in a vertical direction (a Y-Y′ direction in FIG. 2), and barriers 20, which are bar type blocking films, disposed in front of the display module 10, the barriers 20 extending in the vertical direction.
In the above-described stereoscopic image display apparatus, the display module 10 and the barriers 20 are arranged such that light corresponding to the left images L is incident upon the left eye, and light corresponding to the right images R is incident upon the right eye. As a result, the two divided left and right images L and R are separately viewed, whereby a depth effect is realized.
In the conventional parallax-barrier type stereoscopic image display apparatus, which uses a liquid crystal module, the vertical type barriers are arranged parallel to each other in the horizontal direction, and a segment terminal S and a common terminal C are connected to all pixels in order to control all of the pixels to be simultaneously turned ON or OFF. For this reason, a direction in which the barriers are arranged is fixed, with the result that it is possible to view a stereoscopic image only through a screen that displays an image in a fixed direction.
That is, the conventional art has a problem in that, when the position of the eyes of a user is changed as the user moves his/her head or body, the left images may be perceived by the right eye, and the right image may be perceived by the left eye, whereby a reverse-phase stereoscopic image is formed.